LCGB Forums

I am rebuilding the top end of my scoot after a big end failure, and looking at my 'box of useful bits' for an interesting solution..

I have
rapido 225 barrel on 3rd oversize (70.6)
lth reed manifold
wiseco H2 piston 71mm

so my though process is to get a 62mm crank and make a 250ish motor..
bore and port the barrel to suit, cut a boost port, fit reed..
cut windows in the wiseco to suit
put it together and have fun..

however I notice that the ring pegs in the wiseco piston seem to be one above the other and right at the back of the bore, which gives me a problem if I want to cut a boost port, so perhaps my options are to
1. cut two boost ports either side of the ring pegs
2. get another piston (eg AF wossner @71mm)
3. sell some or all of the bits and buy something else

has anyone else got any interesting ideas, advice or opinions worth considering?

Not too helpful at the moment, but Eden is your man for this sort of thing.
If you do face book he's on there.
He might do The Mortons Forum (it might still be called scooterotica)
The H2 pistons are quite sort after so it might make sense to sell and go the AF route for ease.

Have a look @ this piston:

ebay 162119733777

I can’t vouch for it fitting as I use OEM Suzuki pistons in my Ø71 mm Rapido. Mine is also only piston ported but grunty enough for two-up work & even then possibly a tad under-geared (strong Pacemaker with 18 x 46 six plate)

What you propose to do sounds very interesting & likely to yield good results.

‘Stroking’ suits the Rapido IMHO as it tames the timing & allows you to achieve a better set-up. My own has a 61 mm crank.

Boost ports wherever they will fit tend to improve such a motor in terms of power & cooling.

As for cutting the inlet side of the piston, opinion varies on precisely what form that should take. I’d refer to a good two stroke tuning guide if I were you on that....

I hope that all helps.